#include <Key.h>

unsigned char Key_Read(){
	unsigned char temp = 0;
	
	P44 = 0,P42 = 1,P35 = 1, P34 = 1;
	if(P33 == 0)temp = 4;
	if(P32 == 0)temp = 5;
	if(P31 == 0)temp = 6;
	if(P30 == 0)temp = 7;
	P44 = 1,P42 = 0,P35 = 1, P34 = 1;
	if(P33 == 0)temp = 8;
	if(P32 == 0)temp = 9;
	if(P31 == 0)temp = 10;
	if(P30 == 0)temp = 11;	
	P44 = 1,P42 = 1,P35 = 0, P34 = 1;
	if(P33 == 0)temp = 12;
	if(P32 == 0)temp = 13;
	if(P31 == 0)temp = 14;
	if(P30 == 0)temp = 15;
	P44 = 1,P42 = 1,P35 = 1, P34 = 0;
	if(P33 == 0)temp = 16;
	if(P32 == 0)temp = 17;
	if(P31 == 0)temp = 18;
	if(P30 == 0)temp = 19;
	
	return temp;
}